Criterion validity of the Physical Activity Scale (PAS2) in Danish adults.

BACKGROUND: The Physical Activity Scale (PAS2) was developed to measure physical activity (PA) during work, transportation and leisure time, in the Danish adult population. The objective of this study was to assess the criterion validity of PAS2 against a combined accelerometer and heart rate monitor in Danish adults and to investigate if the criterion validity differed by socio-demographic factors and body mass index. METHOD: A total of 330 Danish adults (mean age = 46.7 years, 38.5% men) participating in the Health2008 study completed the PAS2 questionnaire and wore a combined accelerometer and heart rate sensor for seven days. Average daily estimates from PAS2 were categorised into time spent in sedentary behaviour, light PA, moderate PA and vigorous PA and were compared to the objective measures. RESULTS: PAS2 accounted for 19.5 hours/day on average. Time spent in sedentary behaviour, light and moderate-intensity PA was weakly correlated with objective data (polychoric correlation coefficients (PCC): 0.18-0.20), whereas vigorous intensity PA was moderately correlated (PCC: 0.54, p = 0.04). Mean bias was -2.3 hours/day (95% limits of agreement (LoA): -9.04 to 4.34) for sedentary behaviour, 1.68 hours/day (LoA: 8.02 to -4.62) for light activity, 0.55 hours/day (LoA: 3.37 to -2.26) for moderate activity and 0.12 hours/day (LoA: 0.57 to 0.33) for vigorous activity. Criterion validity was lower in women, in participants who were above 40 years, overweight, had short education and were unemployed. CONCLUSIONS: PAS2 overestimated time spent on light, moderate and vigorous intensity PA and underestimated time spent on sedentary behaviour. Validity differed by key socio-demographic characteristics

The Simple 10-Item Predicting Asthma Risk in Children Tool to Predict Childhood Asthma—An External Validation

Background: External validation of prediction models is important to assess generalizability to other populations than the one used for model development. The Predicting Asthma Risk in Children (PARC) tool, developed in the Leicestershire Respiratory Cohort (LRC), uses information on preschool respiratory symptoms to predict asthma at school age. Objective: We performed an external validation of PARC using the Avon Longitudinal Study of Parents and Children (ALSPAC). Methods: We defined inclusion criteria, prediction score items at baseline and asthma at follow-up in ALSPAC to match those used in LRC using information from parent-reported questionnaires. We assessed performance of PARC by calculating sensitivity, specificity, predictive values, likelihood ratios, area under the curve (AUC), Brier score and Nagelkerke's R2. Sensitivity analyses varied inclusion criteria, scoring items, and outcomes. Results: The validation population included 2690 children with preschool respiratory symptoms of whom 373 (14%) had asthma at school age. Discriminative performance of PARC was similar in ALSPAC (AUC = 0.77, Brier score 0.13) as in LRC (0.78, 0.22). The score cutoff of 4 showed the highest sum of sensitivity (69%) and specificity (76%) and positive and negative likelihood ratios of 2.87 and 0.41, respectively. Changes to inclusion criteria, scoring items, or outcome definitions barely altered the prediction performance. Conclusions: Performing equally well in the validation cohort as in the development cohort, PARC is a valid tool for predicting asthma in population-based cohorts. Its use in clinical practice is ready to be tested

Early-life respiratory tract infections and the risk of school-age lower lung function and asthma: a meta-analysis of 150 000 European children.

BACKGROUND: Early-life respiratory tract infections might affect chronic obstructive respiratory diseases, but conclusive studies from general populations are lacking. OBJECTIVE: To examine if children with early-life respiratory tract infections had increased risks of lower lung function and asthma at school-age. METHODS: We used individual-participant data of 150 090 children primarily from the EU Child Cohort Network to examine the associations of upper and lower respiratory tract infections from age 6 months to 5 years with forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, forced expiratory flow at 75% of FVC (FEF75), and asthma at a median age of 7 (range 4 to 15) years. RESULTS: Children with early-life lower, not upper, respiratory tract infections had a lower school-age FEV1, FEV1/FVC and FEF75 (Z-score (95% CI): ranging from -0.09 (-0.14, -0.04) to -0.30 (-0.36, -0.24)). Children with early-life lower respiratory tract infections had a higher increased risk of school-age asthma than those with upper respiratory tract infections (OR (95%CI): ranging from 2.10 (1.98, 2.22) to 6.30 (5.64, 7.04)), and from 1.25 (1.18, 1.32) to 1.55 (1.47, 1.65)), respectively). Adjustment for preceding respiratory tract infections slightly decreased the strength of the effects. Observed associations were similar for those with and without early-life wheezing as proxy for early-life asthma. CONCLUSION: Our findings suggest that early-life respiratory tract infections affect development of chronic obstructive respiratory diseases in later life, with the strongest effects for lower upper respiratory tract infections